European research cannot ignore key questions on energy consumption of communication networks, like: "Is the current growth of energy consumption in telecom infrastructures sustainable?"; "Can we generate and transport enough electricity to provide 100 Mb/s access to all in metropolitan areas?"; "Are optical technologies more energy-friendly than electronics?"; "Is the Internet protocol suite needlessly wasting energy?"The TREND NoE aims at integrating the activities of major European players to quantitatively asses the energy demand of current and future telecom infrastructures, and to design energy-efficient, scalable and sustainable future networks, considering both the backbone, and the wireless and wired access segments.Multi-lateral research activities in TREND will take a holistic approach to energy-efficient networking, by:•\tcollecting data to assess the power consumption of terminals, devices and infrastructures, to quantify the current energy needs and their expected evolution and scaling laws;•\tidentifying energy-friendly technologies, devices, protocols and architectures, and evaluating how they can be introduced in operational networks;•\tdefining new energy-aware network design criteria, balancing the attention to optimal performance and resource allocation with the minimization of energy requirements;•\texperimentally proving the effectiveness of the proposed approaches.The TREND consortium comprises equipment manufacturers, network operators, and university research centers with complementary expertise, and with strong previous involvements and worldwide reputation in matters related to energy consumption in networking. Their synergistic work and dissemination activities in TREND will raise the consciousness on the environmental impact of network infrastructures, and will provide guidelines for an energy-aware evolution of the Internet, thereby reinforcing the leading European position in designing a sustainable future.